Cutting device

Abstract

The present invention relates to a cutting device for a floor processing machine, which has improved wear resistance.

Description

[0001] Divisional application

[0002] This application is a divisional application. The application number of the original application is 201680045487.2, the filing date is July 11, 2016, and the invention title is "Cutting device". Technical field

[0003] The present invention relates to a cutting device for a surface processing machine, in particular a milling machine, the cutting device having a carrier on which a cutting insert is fixed, wherein the carrier has a base part on which a holding attachment including a receiving part is protrudingly mounted, wherein the cutting insert is at least partially arranged in the receiving part, and wherein a fixing attachment is arranged on the fixing side opposite the holding attachment.

[0004] Furthermore, the present invention relates to a cutting device for a surface processing machine, in particular a milling machine, the cutting device having a carrier on which a cutting insert is fixed, wherein the carrier has a base part, and wherein a fixing attachment is arranged on the fixing side of the base part. Background art

[0005] Such a cutting device is known from DE 10 2011 051 520 B4. As shown in this document, the cutting device includes a base part and a carrier, which can also be referred to as a chisel holder in the present invention. The base part can be fixed to the cutting roller of the surface processing machine. The chisel holder is inserted with its holding attachment into the plug-in receiving part of the base part and can be fastened there by means of fixing bolts. The chisel holder itself has a chisel receiving part in which a round-bar chisel can be replaceably received. The round-bar chisel usually has a chisel head and a chisel shank. The round-bar chisel is inserted into the chisel holder by means of the chisel shank. The head bears the cutting tip, which is made of hard metal.

[0006] The cutting device known from DE 10 2011 051 520 B4 is optimized in terms of wear. For this purpose, a wear system is formed in which the round-bar chisel forms the actual wearing part. The chisel holder undergoes multiple chisel replacements until the chisel holder reaches its wear limit. The expensive base part has to be replaced relatively rarely.

[0007] Recently, there has been an effort to use chisels with cutting tips made of superhard materials. As superhard materials, for example, one of the following materials can be used:

[0008] Diamond, single-crystal diamond, polycrystalline diamond, sintered diamond, chemically deposited diamond, physically deposited diamond, natural diamond, infiltrated diamond, diamond film, thermally stable diamond, silicon diamond, silicon carbide, cubic boron nitride, and compounds of the foregoing substances.

[0009] In the present invention, superhard materials should in particular be understood as materials having a hardness in the range of 80 to 130 GPa.

[0010] Such cutting inserts are very wear-resistant and pose completely new requirements on the cutting system. Cutting elements with superhard materials are known, for example, from US 7,600,823 B2. Summary of the Invention

[0011] The object of the present invention is therefore to provide an effective cutting device for a floor working machine, which is characterized by an improved wear resistance.

[0012] This object is achieved in that the cutting insert has a cutting tip comprising a superhard material, and the retaining attachment carries hard material elements in the region between the cutting tip and the base part, at least in the region of its front part in the feed direction.

[0013] By means of the cutting tip made of superhard material, an almost constant cutting action can be ensured for a long time. Here, in order to prevent excessive wear, the retaining attachment is provided with hard material elements in the region between the cutting tip and the base part, at least in the region of its front part in the feed direction. By means of the cutting tip made of superhard material, an almost constant cutting action can be ensured for a long time. Here, in order to avoid erosion and subsequent breakage of the cutting tip due to the eroded cross-sectional geometry of the retaining attachment, hard material elements are arranged on the retaining attachment according to the invention. This arrangement deliberately involves the fact that the hard material elements are arranged in the front in the feed direction. It has been shown that the floor material removed during the application runs turns obliquely from the cutting tip in a direction opposite to the feed direction and slightly towards the base part of the carrier. Accordingly, the hard material elements protect this wear region. Furthermore, it has been shown that another volume flow of floor material is undesirably guided from the cutting tip over the front side of the retaining attachment towards the support. This secondary wear also causes a severe erosion process on the front region of the retaining attachment, which is significantly reduced according to the invention by means of the hard material elements. Therefore, due to the hard material elements according to the invention, the erosion of the retaining attachment can be reduced and the service life of the carrier can be significantly increased. In particular, this also makes it possible to coordinate the service life of the superhard cutting tip with the service life of the carrier, such that they reach their wear limits almost simultaneously with an optimal design.

[0014] According to the invention, it can be provided that the cutting insert is held non-rotatably in the carrier. In this way, the vibrations during the tool action are reduced, which can cause the superhard material to break.

[0015] According to the invention, it can also be provided that the cutting insert has a head on which the cutting edge is fixed, and the head is at least partially made of a material whose wear resistance is less than that of the cutting edge but greater than that of the material of the retaining attachment. In this way, the materials can be coordinated with each other in a cost-optimized manner, and for this purpose, the carrier is worn as evenly as possible. Thereby, such a cutting system is produced in which, in the optimal state, the cutting edge and the carrier reach their wear limits simultaneously.

[0016] Preferably, for this purpose, the head can be made of hard metal.

[0017] A conceivable variant of the invention is configured such that the cutting insert has a shank, and the cutting insert is inserted into the receiving part of the retaining attachment by means of the shank. Preferably, the cutting insert is pressed into the receiving part or is received in the receiving part in a form-fitting manner, for example, welded in the receiving part. Stable support of the cutting insert can be achieved by means of the shank. In addition, the cutting insert can be precisely oriented in the receiving part, so that reproducible production can be simply achieved.

[0018] For this, a conceivable variant of the invention is that the cutting insert forms a concave transition part in the transition region between the head and the shank, such that the receiving part forms a convex transition part in this region, and a gap region filled with a composite material, especially solder, is provided in the region of this transition part. Thereby, a manufacturing-optimized structure is achieved. In particular, the harmful stresses in the transition region between the head and the shank can be reduced, so that fracture in this region can be prevented during tool insertion. In addition, this structure has proven to be advantageous because the notch stresses are significantly reduced during the application operation. This is particularly advantageous when the milling depth to be processed is very small. In this case, increased lateral forces sometimes occur.

[0019] A particularly preferred variant of the invention is that the head of the cutting insert widens from the cutting edge in the direction of the retaining attachment.

[0020] In this way, the head forms a guiding surface, and the geometric structure of the guiding surface can be configured such that the removed ground material flowing along the head can be guided away by the carrier material, thereby reducing friction.

[0021] A feasible variant of the invention is that the cutting edge has a support body, and the support body is connected to the head of the cutting insert, preferably by welding, such that one or more intermediate layers are applied on the support body, and a covering layer is applied on the outermost side of the intermediate layer facing away from the support body, and the material of the covering layer is harder than the material of the intermediate layer.

[0022] Such a stable cutting edge can be constructed through this layer structure. The cutting edge is particularly very wear-resistant and can also reliably resist the occurring impact loads.

[0023] A possible variant of the present invention is that the hard material element is formed by coating curing, such as surfacing, plasma coating curing, etc.; and / or the hard material element is formed by one or more hard material segments, and the hard material segments are connected to the holding attachment.

[0024] As the hard material segment, for example, a hard metal element can be used, and the hard metal element is welded to the holding attachment.

[0025] In the present invention, such a cutting device can also be constructed, in which the holding attachment has a support section away from the base body, such that the cutting insert at least partially covers the support section with its head, and the hard material element is guided into the area of the support section under the head.

[0026] In this way, the transition area between the head and the holding attachment is effectively protected against erosion by the hard material element. This prevents erosion of the support surface under the head, which would cause the cutting insert to fail quickly.

[0027] A particularly preferred variant of the present invention is configured such that the cutting insert has a flow guiding surface, which is configured such that the ground material peeled off by the cutting edge at least partially passes over the base body part of the carrier. Thereby, the wear effect on the carrier is significantly reduced.

[0028] It is conceivable that the hard material element is arranged arcuately around the receiving part of, for example, a cylindrical holding attachment, or is applied circularly around the receiving part on the holding attachment.

[0029] According to the corresponding intended use, the hard material element can be arranged on an arc in the range of 5 to 360 degrees.

[0030] It is also conceivable to completely surround it in order to provide the best protection.

[0031] It can be particularly advantageously provided that the arcuate hard material element extends in the circumferential direction and the feed direction in front of the cutting insert over a length greater than the diameter or the maximum cross-sectional dimension of the receiving part. In this way, the receiving area for the cutting insert is effectively and simply protected against wear.

[0032] In particular, it can also be provided that the hard material element has an extension distance in the direction of the longitudinal central axis of the receiving part, and this extension distance is equal to or greater than the height of the receiving part in this direction.

[0033] The object of the present invention is also achieved by a cutting device for a surface processing machine, in particular a milling machine, which cutting device has a carrier on which cutting inserts are fixed, wherein the carrier has a base part, and wherein fixing attachments are arranged on the fixing side of the base part. According to the invention, the cutting device is configured such that the base part bears on the processing side facing away from the fixing side a cutting element fixedly connected to the carrier, wherein the cutting element bears a cutting tip made of a superhard material, wherein the cutting element bears a fixing piece, on which a projection is connected on the rear side counter to the feed direction, and the fixing piece and the projection are supported on the carrier by a bearing surface.

[0034] The fixing piece arranged in the front in the feed direction reliably guides away the removed surface material from the cutting tip. In this regard, the present invention has found that there is a maximum wear pressure primarily in the region of the cutting tip. The superhard cutting tip reliably intercepts this wear. Immediately following the cutting tip, the surface material spreads out in the flow direction, whereby the wear pressure continuously decreases. The always high wear pressure is reliably intercepted by the fixing piece. When the surface material has passed the fixing piece, it then enters a state of expansion that can be reliably borne by the carrier made of, for example, steel. In this way, an efficient wear system is provided. In order to achieve reliable support of the cutting element, according to the invention the cutting element has a rear projection which is supported on the carrier. In this way, bending stresses can be reliably guided away. In addition, the rear projection also protects the rear carrier region against erosion.

[0035] It is particularly preferably provided that the fixing piece and the projection are supported on the carrier by a material-fit connection, in particular solder.

[0036] A reliable support of the connection pair is achieved via the solder. In particular, the integral support can be configured without gaps. Furthermore preferably, the cutting element can be made of a hard material, such as hard metal, which is sensitive to fracture stress. If there is then a material-fit connection support at this time, harmful gap regions can be avoided in the support region, thus facilitating reliable fracture-resistant support.

[0037] According to the invention, it is preferred that the fixing piece is arranged in front of the holding attachment of the carrier in the feed direction and at least partially covers the holding attachment. The cutting element can be held on the base part of the carrier in an exposed manner by the holding attachment, and the fixing piece thereby protects the holding attachment. In this way, an invasive cutting geometry can be achieved.

[0038] A conceivable variant of the present invention is configured such that the fixing piece has an inclined deflecting surface on the opposite side in the feed direction, and the deflecting surface is configured such that the removed surface material is deflected in the direction of the side of the carrier.

[0039] Another wear optimization can be achieved in such a way that the cutting edge of the cutting element is preferably configured asymmetrically and, for example, has a larger volume in the region radially outside thereof than in the region radially inside thereof. In this way, an increased wear volume is formed in the region radially outside that is subjected to the greatest cutting action.

[0040] A reliable support for the cutting edge can be achieved in such a way that the cutting edge is supported on the head of the cutting element by means of a connecting element against the feed direction. Description of the Drawings

[0041] The present invention will be described in detail below with reference to the embodiments shown in the drawings.

[0042] Wherein:

[0043] Figure 1 A carrier with a cutting insert is shown in a perspective partial cross-section.

[0044] Figure 2 Is shown schematically Figure 1 A side cross-sectional view of the details in

[0045] Figure 3 Shows according to Figure 2 A top schematic view of the first variant of

[0046] Figure 4 Shows according to Figure 2 A top schematic view of the second variant of

[0047] Figure 5 A side partial cross-sectional view of a carrier with a cutting insert in another configuration of the present invention is shown.

[0048] Figure 6 Shows Figure 5 A detailed cross-section along cutting line VI in

[0049] Figure 7 Shows a longitudinal cross-sectional schematic view of the cutting edge of a cutting insert according to a variant of the present invention according to Figures 1 to 6 And Figure 8

[0050] Figure 8 Another variant of a carrier with a cutting element is shown in a perspective side view. Detailed Description of the Invention

[0051] Figure 1 ​shows a carrier 10 made of steel. The carrier 10 has a base part 11 including a fixed side and a machining side. Four support surfaces 12 are arranged in the area of the fixed side. The support surfaces 12 are angled with respect to each other. There are a front support surface and a rear support surface 12. The front support surface 12 extends in the area of the lower side of the guard plate 13 of the base part 11. The guard plate 13 is arranged at the front in the feed direction. In addition, a fixing attachment 14 is arranged in the area of the fixed side of the carrier 11. In the present invention, the fixing attachment 14 can also be configured as a plug-in attachment, as Figure 1 exemplarily shown. The fixing attachment 14 can have a fixing receptacle 15 on the rear side opposite to the feed direction. The fixing attachment 14 has two support surfaces 16 on the front side, and the two support surfaces are arranged spaced apart from each other via a recess 17. The fixing receptacle 15 is configured to receive the end of a clamping bolt. The clamping bolt introduces a pulling force extending in the longitudinal direction of the fixing attachment 14 into the fixing attachment 14 via the fixing receptacle. For this purpose, this force acts not only in the direction of the longitudinal axis of the fixing attachment 14, but also presses the two front support surfaces 16 against the corresponding mating surfaces of the replacement holding member lower part.

[0052] The base part 11 has a holding attachment 20 in the area of the machining side. The holding attachment 20 projects above the base part 11 having a preferably cylindrical projection, as Figure 1 shown. The holding attachment 20 has a tapered constriction at the end side. The free end of the tapered constriction is formed by a support section 24. A hole is machined in the support section 24, and this hole forms a receiving part 21. As Figure 1 shown, the holding attachment 20 is provided with a hard material element 22 in a circumferential manner in the area of the conical surface 23. The hard material element 22 is implemented as a surfacing part. A cutting insert 30 is placed in the receiving part 21. The cutting insert 30 carries a cutting tip 31, and the structure of the cutting tip will be described in detail later. The cutting tip 31 is connected to the head 33 of the cutting insert 30 via a connecting member 32 made of, for example, hard metal. A rod part 34 is molded on the head 33. The rod part 34 is inserted into the receiving part 21. The member composed of the head 33 and the rod part 34 can be made of, for example, hard metal. In particular, it is selected such that the hardness of this member is greater than the hardness of the carrier 10, but less than the hardness of the cutting tip 31.

[0053] As can be seen from Figure 2 the rod part 34 is transitioned to the head 33 via a concave transition part. The opposite receiving area of the receiving part 21 is correspondingly configured as convex. As Figure 2As shown, a clearance region is formed between the rod portion 34 and the receiving portion 21, and this clearance region is filled with solder 35. Thereby, the head 33 is also supported on the support section 24 especially by means of the solder. This is advantageous because the risk of breakage is avoided via this gapless connection. The stress peak in the transition region between the rod portion 34 and the head 33 is reduced via the concave / convex mating surfaces. Instead of the solder 35, any other material connection can also be provided. Furthermore, it is conceivable to shrink the rod portion 34 into the receiving portion 21. Furthermore, it can be seen from Figure 2 the hard material element 22, which surrounds and holds the attachment 20 in the region of the conical surface 23. For this purpose, the hard material element 22 is constructed and arranged such that it completely covers the height of the receiving portion 21 with its height h, thereby forming a suitable protection against cavities. As Figure 2 shown, in the present invention it is also conceivable that the build-up portion does not constantly have the same thickness. Instead, a variable thickness is conceivable, in order to achieve suitable wear characteristics. For example, it can be provided that the thickness of the hard material element 22 decreases in the direction of the longitudinal central axis of the cutting insert.

[0054] The hard material element 22 can be applied circumferentially. However, it is also conceivable that the hard material element 22 is arranged on an arcuate region on the holding attachment 20, as can be seen from Figure 3 and Figure 4 As Figure 3 shown, preferably the arcuate length l in the circumferential direction of the holding attachment 20 should be chosen to be greater than the diameter of the receiving portion 21, or greater than the diameter of the head 33. The hard material element 22 also does not have to have the same thickness in the circumferential direction. Instead, it can also be provided that the thickness is variable in the circumferential direction, preferably decreasing in the opposite direction to the feed direction.

[0055] In Figure 5 and Figure 6 another embodiment of the present invention is shown. As Figure 5 shown, the hard material element 22 consists of hard material segments mounted on the holding attachment 20. The hard material element 22 can be formed, for example, by hard metal elements, which are materially connected to the holding attachment 22. As Figure 6 shown, the hard material element 22 can consist of hard material segments 22.1. For example, the hard material segments 22.1 can be configured in a flat shape. It is also conceivable that, as Figure 6As shown, the hard material section 22.1 has a covering section 22.2, and the fixing attachment 22.3 is molded on the covering section. The hard material section 22.1 is introduced into the fixing receiving section 22.4 of the holding attachment 22 with the fixing attachment 22.3. The hard material section 22.1 is joined in a form-fitting manner, in particular welded, to the holding attachment 22 in the region of the fixing attachment 22.3 and in the region of the underside of the covering section 22.2. From Figure 7 An exemplary configuration of the cutting tip 31 can be seen therefrom. For this purpose, a support 31.1 made of, for example, hard metal is used, and an intermediate layer 31.2 is applied on the support. It is also conceivable to use two or more intermediate layers 31.2. A covering layer 31.3 is applied on the intermediate layer 31.2. Preferably, the covering layer 31.3 has a polycrystalline diamond content. The intermediate layer 31.2 also has a polycrystalline diamond content. For this purpose, the polycrystalline diamond content in the covering layer 31.3 is greater than that in the intermediate layer 31.2.

[0056] Figure 8 Another variant of the present invention is shown. As can be seen from this schematic view, the carrier 10 basically corresponds to the construction of the carrier 10 according to Figure 1 , so that only the differences will be discussed below. Different from the carrier 10 according to Figure 1 , the carrier 10 according to Figure 8 has a holding attachment 25, which is molded on the base part 11 away from the fixing attachment 14. The holding attachment 25 has two angled support surfaces 26 and 27. For this purpose, the support surface 27 faces the feed direction V, and the support surface 26 is opposite to the feed direction. In the case of form-fitting connection, for example by welding, the cutting element 40 is slipped onto the two support surfaces 26 and 27. The cutting element 40 has a head 43, and the head forms a fixing part 45. The fixing part 45 has two turning surfaces 46 inclined in the feed direction on the side. A projection 44 is molded on the rear side of the fixing part 43. The cutting element 40 is placed on the support surfaces 26 and 27 by means of the fixing part 43 and the projection 44, as described above. In addition, the head 43 carries the cutting tip 31, and the cutting tip is basically constructed in a similar manner to the cutting tip 31 of the variant according to Figures 1 to 7 . However, the cutting tip 31 is constructed asymmetrically with respect to its longitudinal central axis and has a larger volume in its radially outer region than in its radially inner region. Thereby, a larger wear volume is provided in the region of the outer cutting edge of the cutting tip 31. The cutting tip 31 is supported on the head 33 in the direction opposite to the feed direction via the connecting piece 32 and fixed there, preferably by form-fitting connection, in particular by welding.

Claims

1. Cutting device for a floor working machine, the cutting device having a carrier (10) to which a cutting element (40) is fixed, wherein, The carrier (10) has a base part (11), wherein a fixing attachment (14) is arranged on the fixing side of the base part (11), characterized in that the carrier (10) has a retaining attachment (25), which is molded on the base part (11) away from the fixing attachment (14), and the retaining attachment (25) has two supporting surfaces A (26) and a supporting surface B (27) which are angled with each other, the supporting surface B (27) facing the feed direction V, and the supporting surface A (26) opposite to the feed direction, The base part (11) carries a cutting element (40) fixedly connected to the carrier (10) on the processing side facing away from the fixing side, wherein the cutting element (40) carries a cutting tip (31) made of superhard material, wherein the cutting element carries a fixing part (45), to which a projection (44) is connected at the rear side opposite to the feed direction (V), and the fixing part (45) and the projection (44) are supported on the carrier (10) by a support surface A (26) and a support surface B (27), The fixing element (45) has an inclined deflection surface (46) on the opposite side along the feeding direction, and the deflection surface is configured so that the peeled ground material is guided toward the side of the carrier (10). The blade tip (31) of the cutting element (40) is designed asymmetrically with respect to its longitudinal center axis and has a larger volume in its radial outer region than in its radial inner region. The cutting element (40) has a head (43) which forms a fixing element (45).

2. The cutting device according to claim 1, wherein The fixing element (45) and the projection (44) are supported on the carrier (10) by means of solder.

3. The cutting device according to claim 1, characterized in that The fixing element (45) and the projection (44) are connected to the carrier (10) by means of a material fit.

4. The cutting device according to claim 1 or 2, characterized in that The fixing element (45) is arranged in front of the retaining attachment (25) of the carrier (10) in the feed direction (V) and at least partially covers the retaining attachment.

5. The cutting device according to claim 1 or 2, characterized in that, The blade tip (31) is supported by means of a connecting piece (32) on a head (43) of the cutting element (40) counter to the advancing direction (V).

6. The cutting device according to claim 1 or 2, characterized in that, The ground processing machine is a road milling machine.

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